Apply a formula from check box in VBA

I've been struggling with this for a while now, so i realllyyyy hope someone can help!

I have this code

 Private Sub CheckBox1_Click()
 If OptionButton1.Value = True Then
 Sheets("Sheet1").Select
 Range("J4").Select
 Selection.FormulaArray = "=IFERROR(INDEX(C$2:C$14, SMALL(IF($B$2:$B$14=1, ROW($B$2:$B$14)-1),ROWS(G$2:G2))),"")"
 Selection.Columns.AutoFit

 ElseIf OptionButton1.Value = False Then
 Range("J4").Value = " "
 End If

 End Sub

Where I'm trying to get the formula perforned in cell J4. It just wont do it! And I dont really get why!

Please Help